Maybe I am asking too much of my 45 but I have been chasing the idle on it for the last 3 years with different iterations of motor changes to get it back to stock. When the engine is cold I have a nice “putt – putt” idle (spark fully advanced), so slow the generator light flickers. When the engine warms up during a high speed run the idle speed is high at the next stop, almost racing. I have to retard the spark and it gets slower but not at a speed I would call an idle, more like a fast idle. If I turn the hot engine off and start it 15 minutes later the idle is back to the “putt-putt” mentioned above.
Regardless of the iterations in getting this engine right it now has the following:
New barrels, pistons, rings, valves, valve springs, head and base gaskets.
Aluminum #5 heads with Teflon gaskets.
The intake manifold has the extension between the carb and the manifold, some call this a heat blocker but I have read it does not block heat but moves the carb out from between the hot cylinders. All the mating surfaces look flat and mate without any noticeable warps.
The carb is an M88 with adjustable high speed. The location for the high speed jet is plugged with a brass plug and so is the other hole.
New throttle shaft with barely discernable “wiggle” in the throttle shaft bushings. Just to be on the safe side I squashed an “O ring” under the throttle arm to seal better as a last resort.
I have cleaned the carb including making sure the two little holes where the butterfly closes are open.
The vent in the venturi is clear.
The nozzle is not stuck but it does not readily fall out when the bowl and spring are removed. A few thumps on the carb body by hand and gravity is all it takes to get it out.
The venture is tight and I have not removed it.
This sounds like an air leak to me but I can not figure out where it is.
Regardless of the iterations in getting this engine right it now has the following:
New barrels, pistons, rings, valves, valve springs, head and base gaskets.
Aluminum #5 heads with Teflon gaskets.
The intake manifold has the extension between the carb and the manifold, some call this a heat blocker but I have read it does not block heat but moves the carb out from between the hot cylinders. All the mating surfaces look flat and mate without any noticeable warps.
The carb is an M88 with adjustable high speed. The location for the high speed jet is plugged with a brass plug and so is the other hole.
New throttle shaft with barely discernable “wiggle” in the throttle shaft bushings. Just to be on the safe side I squashed an “O ring” under the throttle arm to seal better as a last resort.
I have cleaned the carb including making sure the two little holes where the butterfly closes are open.
The vent in the venturi is clear.
The nozzle is not stuck but it does not readily fall out when the bowl and spring are removed. A few thumps on the carb body by hand and gravity is all it takes to get it out.
The venture is tight and I have not removed it.
This sounds like an air leak to me but I can not figure out where it is.
Comment